GSSL HELP THREAD!!!

[Nadege]

I traced the signal but suddenly the tension change and now I've got -17v and +12v !!!! And it's really less stable. I think something burned... But I didn't notice any smoke or strange smell.
:?: :?: :?:

On the other hand, I'm a bit confused about this trace... I don't understand what is in the way of +15/-15 v to the Ne5534 of the DBX emulation to bring it to +12/-12v ??? (All I see is that the way is really simple, is just a straight way from the point with +15v to the pin 7 of the ne5534 without any component in the middle)

I'm not sure I'm clear because of my english :?

 

[gyraf]

-17v and +12v

Something is wrong.

Check (and possibly replace) your negative regulator(s)..

 

[Nadege]

How should I check it? Is there a special procedure?

 

[gyraf]

Nope.

If you're unsure, try replacing with a known-good specimen..

Jakob E.

 

[Nadege]

I replace the 7915, 7815, and 79l12 but I still have the same trouble, i.e around -17.5v and around +11.22 v I looked for shorts, but couldn't found anything wrong.


Thanks for your help Jakob

 

[Nadege]

Ok I checked the trace again looking for shorts, and now I'm back to the original situation, no +12-12 at the ne5534 of the vca emulation but +15-15

Grrrrrr... :evil:

 

[gyraf]

Take another look at the PCB..

The VCA emulation driver opamps are connected to the jumpers marked +15 and -15.

Jakob E.

 

[Nadege]

Ok, I had another look, all seems to be ok exept for this +15-15 of the NE5534 of the VCA emulation.

Could anybody explain how the tension +15-15 is put down to +12-12 in this circuit. I'm totally new at DIY and don't really understand this part of the schematics.

For me, I only see the +15-15 v rail witch is feeding directly the ne5534 whitout anything in his way.....

I think I'm going to build a second clone to see what's happening..

Thanks guys

 

[gyraf]

I don't understand why you expect anything other than +/-15V at those opamps, when it's clear to see (if you inspect the pcb) that they ARE CONNECTED to the +/-15V lines?

 

[Nadege]

just because on the schematics is see that the tension must be +12/-12. Is there something wrong in the schematics?

I'm using the schemativs from Gyraf and it's in the little box on the left down the page "VCA emulation"

Maybee all is alrigth after all...

 

[gyraf]

Yes, the schematic says +/-12 at the vca-driver opamps, where it should say +/-15.

Maybee all is alrigth after all...

You bet..

Jakob E.

 

[Nadege]

Fine, I'm really happy :grin: :grin: :grin: :grin:

nearly becam mad because of this.

Thanks Jakob Now I'll see what happens with the IC in place and with audio going thru the unit, Hope all is going to be ok

:wink:

 

[indigom]

Hello all,

I'm trying to get a second SSL board working. It passes audio and compreses, meter works, but one channel is a few db lower that the other on all input audio.

It happens the same even in bypass.

Here's what I've done to troubleshoot so far:
-I've resoldered the input/output connections at jacks and checked the + - orientation on my connectors and they seem fine. Verified connectivity with ohmmeter.
-Swapped out the VCAs, 5534s, 5532s, Tl072 and TL074s for no change.
-I visually verified the resistors from the working board to the almost working board, and haven't found a problem yet.
-Tested the new control switch board with the working SSL board and it works good.
-Swapping the input channel cables keeps the problem the same, swapping the output cables moves the problem to the other channel.

What I haven't done is:
-Verify capacitor values
-Swap out the sidechain VCA

So this is all I can think of in troubleshooting today, does
anyone have suggestions?

thanks!
-Jay

 

[moogfrotee]

sorry to intemit.
I just realised something that I wan´t to share.

I built two SSL from audio kitchen PCB´s so far, that was my first experience and I´m still learning.

The second SSL has a problem when release is switched to auto position:
distortion, but not bad sounding rather very detailed and schmothh.
The more compression the more distortion.

I just left it this way because I´m to much a beginner to realy understand this to the detail.

Two days ago I found out why this happens in auto mode: because I configured the switch to 6 positions instead of 5.

I have no lettering on the SSL so far thats why it never attracted my attention.

I have no idea whats happening when the switch is like that, but it sounds cool. Could it harm the comp? thats acctualy the only concern I have ,sometimes mh...not realy because apart from that it´s working fine!

When it´s not bad for the comp, I will leave it that way

max

 

[BR]

Hey indogom,
I experienced the same problem with mine and it was a shorted out cap on the output. One of those .1p caps. (thanks Steve for finding that)
Check them with a dmm, and see if any has gone bad or is bad..

Gil

 

[indigom]

[quote author="BR"]Hey indogom,
I experienced the same problem with mine and it was a shorted out cap on the output. One of those .1p caps. (thanks Steve for finding that)
Check them with a dmm, and see if any has gone bad or is bad..

Gil[/quote]

So given this excellent advice from Gil and Steve, I went right for the problem. It was one leg of a 100pF cap in the Output Section which was soldered against something that it shouldn't have been. A little de-soldering braid on it and it's fixed. The thing sounds great now, nice and open with appropriate levels on both channels.
:sam: beers for everyone!

cheers!
-Jay

 

[Nadege]

Hi everybody.

Now that my ssl clone has the rigth tension (thanks Jakob) I've got another problem.

The unit is working (compressing, meter ok, power LED ok, audio passing thru the unit, ...) but.. :evil:

- I've got a very loud Hum, on both side at the same level... I read what was said in the thread and try some stuff like moving the transformer out of the box, checking all my componant value, looking for shorts, made some continuity test between the main PCB and the control PCB, but nothing change. Also checked my XLR connection to the PCB

-The Hum gets louder with the make-up pot and don't disapear with the bypass switch. The control are active on the hum i.e. The compression is active on the hum.

-With the Make up pot on "0" both side have the same level, but when the make up increase, only the rigth side increase in level, the left one doesn't change....


I suspect a short in the sidechain circuit, is it possible that this could make this hum and wrong level compensation balance ???

Thanks for your help.

 

[Greg]

Problems in the sidechain would effect both channels the same. So if something is screwy in only one channel, I would look outside the sidechain first.

 

[Nadege]

Ok, I checked the sidechain, all is seems to be alrigth there. Where should I look????

 

[JerryPbury]

I have a Pair of the DBX 202's. Does anyone have a Mouser or Digikey part # for sockets for the PCB? I would prefer not to drill out the current holes to size in the pcb and soldering the 202's in. Also if anyone has a spare 2150 for the side chain let me know a price.

Anyone?

Thanks,

Jerry